/*
 * <<
 * Davinci
 * ==
 * Copyright (C) 2016 - 2017 EDP
 * ==
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * >>
 */

/**
 * Combine all reducers in this file and export the combined reducers.
 * If we were to do this in store.js, reducers wouldn't be hot reloadable.
 */

import { fromJS } from 'immutable'
import { Reducer, ReducersMapObject } from 'redux'
import { combineReducers } from 'redux-immutable'
import { LOCATION_CHANGE } from 'react-router-redux'

import globalReducer from './containers/App/reducer'
import languageProviderReducer from '../app/containers/LanguageProvider/reducer'

/*
 * routeReducer
 *
 * The reducer merges route location changes into our immutable state.
 * The change is necessitated by moving to react-router-redux@4
 *
 */

// Initial routing state
const routeInitialState = fromJS({
  locationBeforeTransitions: null
})

/**
 * Merge route into the global application state
 */
function routeReducer (state = routeInitialState, action) {
  switch (action.type) {
    /* istanbul ignore next */
    case LOCATION_CHANGE:
      return state.merge({
        locationBeforeTransitions: action.payload
      })
    default:
      return state
  }
}

/**
 * Creates the main reducer with the asynchronously loaded ones
 */
export default function createReducer (injectedReducers: ReducersMapObject = {}): Reducer<any> {
  return combineReducers({
    route: routeReducer,
    language: languageProviderReducer,
    ...injectedReducers
  })
}
